I've considered buying a SU-16C as a back-up for my AR-15. Piles and piles of .223 ammo could be useless brass, lead, and copper if my AR-15 goes down in SHTF. Plus...it uses AR-15 mags. Hard to beat that!
I would never buy one instead of an AR-15, though. The AR-15 is the gold standard and there is no comparison.
.45acp, .40 S&W, 9mm, .38 Spl, .380 acp, 22lr
12 gauge, .223/5.56x45mm, 30-30 Winchester
2 Chron. 7:14 Christians must seek His face